In network devices it is important to configure each device in the network properly. If there is any misconfiguration, the network may not work properly. For instance, some devices may have problems connecting or communicating with other devices. The trend in network device manufacturing is to make the configuration process less time consuming and as easy as possible. This is why the idea of “Plug And Play” is very popular and accepted.
In general, a network can include many devices and types of devices, such as computers, printers, servers, switches, and the like, that are interconnected and that can communicate with each other. Also, separate networks can be connected to each other. Typically, separate networks can be connected via a network device such as a router.
Routers are electronic systems that determine the next network point to which a packet should be forwarded toward the packet's destination. Routers are connected to at least two networks and decide which way to send each information packet based on the router's current understanding of the state of the networks it is connected to. Routers can be combined and can include additional components. A router creates or maintains a table of the available routes and their conditions and uses this information along with distance and cost algorithms to determine the best route for a given packet. Typically, a packet may travel through a number of network points with routers before arriving at its destination.
Routers connect networks using a number of methods known in the art. The connection between the routers might be a dial-up connection or a leased line connection. The line can be an XDSL, ATM, Frame Relay, ISDN, X.25, or any other type of line. A router operates at the network layer (layer 3) of the ISO/OSI seven-layer model. Dilip C. Naik, Internet Standards and Protocols, p. 55 (1998).
Routers perform a variety of functions including verifying validity of data packets, queuing a packet for delivery, forwarding the packet, and exchanging routing information with other routers. Routers also typically consult a data structure called a “routing table” to see where the data packet should go next. A routing table can quickly identify a port over which a data packet should be sent if a destination address is known. Id.
Various routing algorithms are used to update the routing table to reflect changes in network topology. Routing protocols implement routing algorithms. Routing protocols operate on network protocols such as IP and Internet Packet Xchange (IPX). Id.
One type of routing protocol is the Routing Information Protocol (RIP). RIP is a protocol used in small and medium sized IP networks for advertising IP routing information. RIP is a dynamic, intradomain, distributed, flat, single path, distance vector routing protocol. Id. RIP is a simple and widely used protocol that uses periodic advertisements. In one network there may be many RIP routers advertising RIP routes periodically.
There are currently two versions of the RIP. RIP version 1 is described in Hedrick, C., “Routing Information Protocol,” RFC 1058 Rutgers University, June, 1988 (RFC 1058), and RIP version 2 is described in Malkin, G., “RIP Version 2,” RFC 2453, Bay Networks, November, 1998 (RFC 2453). Additionally, there is a modification of RIP for Dial on Demand (DoD) links called Triggered RIP, which is described in Meyer, G., et al., “Triggered Extensions to RIP to Support Demand Circuits,” RFC 2091, Shiva, January, 1997 (RFC 2091).